I know, I know. You don't want to bulk up, you just want to "tone." 
If you think another hour on the treadmill or elliptical is going to do that for you, think again. There's only one way to tone muscle and that's to use it. You build muscle by contracting it to overcome the resistance of some force: gravity, your body weight or a dumbbell, for example. The work of overcoming that resistance causes microtrauma in the fibers, and it's the repairing of that microtrauma that builds muscle.
Plenty of women still believe the myth that lifting weights will make them bulky and shredded. Trust me, unless you are willing to spend hours in the gym, monitor every bite you take and probably take male hormones and steroids, lifting weights will not make you bulky. Very few women have the genetic make up and discipline it takes to bulk up. Weight training will, however, make you stronger, leaner and healthier. Here are the top three reasons you really need to begin lifting weights.
1. Muscle burns calories and boosts metabolism. Muscle is more metabolically active than fat. Even at rest, muscle is burning calories just to maintain and remodel muscle proteins. The real metabolic benefit of weight training doesn't come just from adding muscles, though; it comes from using them. The process of repairing exercise-induced microtrauma is energy-intensive, meaning you burn more calories than if your muscles weren't repairing themselves. Because of the active nature of muscle fiber, a more muscular 150-pound woman will burn more calories than a less muscular 150-pound woman because a greater percentage of her weight is made up of active, calorie-consuming tissue.
2. Weight training builds bones. Bone tissue is continuously being broken down to supply the body with minerals and rebuilt to provide structural strength. When bone is subjected to stressful forces--like bearing the weight of the body or overcoming the resistance of weight training--it responds by producing more bone tissue. The U.S. Department of Health and Human Services estimates that more than 50% of women and 20% of men over the age of 50 will suffer a broken bone due to osteoporosis sometime in their lives. You can improve your odds by building strong bones with weight training. As an added bonus, the improved muscle function can also help you maintain your balance which helps prevent falls from happening in the first place.
3. Weight training slows the aging process and fights diseases of aging. Weight training increases the mitochondrial content of muscle tissue. Mitochondria are the powerhouses of the cells, helping generate the energy that fuels cellular activity. With age, our mitochondria can begin to malfunction, resulting in wider cellular damage and visible signs of aging. A number of studies have found that regular exercise including resistance training can slow or even reverse the malfunctioning of mitochondria. Resistance training has also been shown to reduce the risk of type 2 diabetes, lower resting blood pressure and improve blood lipid profiles.
A healthy weight training routine engages all the major muscle groups, trains the muscles to the point of fatigue to maximize the rebuilding process, and allows 48-72 hours of recovery time between training sessions. The benefits of weight training are available to you whatever your age when you start and no matter how inactive you have been. A personal fitness trainer can help you design a safe and effective weight training program just for you.
(photo credit: Michal Hadassah)
